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J Am Coll Cardiol, 2008; 52:1335-1343, doi:10.1016/j.jacc.2008.07.027
© 2008 by the American College of Cardiology Foundation
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CLINICAL RESEARCH: CARDIAC IMAGING

Mortality Incidence and the Severity of Coronary Atherosclerosis Assessed by Computed Tomography Angiography

Matthew P. Ostrom, MD, Ambarish Gopal, MD, Naser Ahmadi, MD, Khurram Nasir, MD, MPH, Eric Yang, MD, Ioannis Kakadiaris, PhD, Ferdinand Flores, BS, Song S. Mao, MD and Matthew J. Budoff, MD*

Division of Cardiology, Department of Medicine, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California

Manuscript received March 3, 2008; revised manuscript received July 11, 2008, accepted July 14, 2008.

* Reprint requests and correspondence: Dr. Matthew J. Budoff, Harbor-UCLA Medical Center, 1124 W. Carson Street, RB2, Torrance, California 90502 (Email: mbudoff{at}labiomed.org).

Objectives: This study investigated whether cardiac computed tomography angiography (CTA) can predict all-cause mortality in symptomatic patients.

Background: Noninvasive coronary angiography is being increasingly performed by CTA to assess for obstructive coronary artery disease (CAD), and minimal outcome data exist for coronary CTA. We have utilized a cohort of symptomatic patients who underwent electron beam tomography to allow for longer follow-up (up to 12 years) than currently available with newer 64-slice multidetector-row computed tomography studies.

Methods: In all, 2,538 consecutive patients who underwent CTA by electron beam tomography (age 59 ± 14 years, 70% males) without known CAD were studied. Computed tomographic angiography results were categorized as significant CAD (≥50% luminal narrowing), mild CAD (<50% stenosis), and normal coronary arteries. Multivariable Cox proportional hazards models were developed to predict all-cause mortality. Risk-adjusted models incorporated traditional risk factors for coronary disease and coronary artery calcification (CAC).

Results: During a mean follow-up of 78 ± 12 months, the death rate was 3.4% (86 deaths). The CTA-diagnosed CAD was an independent predictor of mortality in a multivariable model adjusted for age, gender, cardiac risk factors, and CAC (p < 0.0001). The addition of CAC to CTA-diagnosed CAD increased the concordance index significantly (0.69 for risk factors, 0.83 for the CTA-diagnosed CAD, and 0.89 for the addition of CAC to CAD, p < 0.0001). Risk-adjusted hazard ratios for CTA-diagnosed CAD were 1.7-, 1.8-, 2.3-, and 2.6-fold for 3-vessel nonobstructive, 1-vessel obstructive, 2-vessel obstructive, and 3-vessel obstructive CAD, respectively (p < 0.0001), when compared with the group who did not have CAD.

Conclusions: The primary results of our study reveal that the burden of angiographic disease detected by CTA provides both independent and incremental value in predicting all-cause mortality in symptomatic patients independent of age, gender, conventional risk factors, and CAC.

Key Words: outcomes • CT angiography • cardiac CT • prognosis • coronary calcium

Abbreviations and Acronyms
  AUC = area under the curve
  CAC = coronary artery calcification
  CACS = coronary artery calcium score
  CAD = coronary artery disease
  CHD = coronary heart disease
  CI = confidence interval
  CTA = computed tomography angiography
  EBT = electron beam tomography
  HR = hazard ratio
  MDCT = multidetector-row computed tomography
  ROC = receiver-operator characteristic


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